The present invention relates to bicycle racks and other equipment carriers which mount to a trailer hitch at the rear of a vehicle.
The development of equipment racks, particularly bike racks which mount bikes or other recreational equipment to the exterior of an automobile has undergone a number of evolutionary steps. There are in general three general types of racks: roof racks, trunk racks, and hitch racks. Recently hitch racks, that is equipment carriers that mount to a trailer hitch at the rear of a vehicle, have become more popular. This popularity is related to the rise of the sport utility vehicle and the wide use of trucks for urban passenger vehicles. Whereas in the past a trailer hitch was a fairly specialized item normally only purchased by those with a trailer to pull, now a wide variety of vehicles come with trailer hitches as standard equipment or as part of a package of options.
A rack which attaches to a trailer hitch has many advantages. A trailer hitch provides a standard interface designed to support substantial loads. Installing and removing a rack from a trailer hitch is normally simpler then mounting a carrier directly to a vehicle. A stronger equipment rack, capable of carrying a larger number of bikes or other equipment, is more easily accommodated by a rack mounted to a hitch which is designed to support substantial hitch loads. The rack is also located at the rear of the vehicle where aerodynamic drag is not affected by the presence of additional equipment by virtue of being positioned in the turbulent wake region behind a vehicle.
One problem with a rack or cargo carrier which mounts to a trailer hitch at the rear of a vehicle is that the rack may prevent access to the rear door of the vehicle. Although some racks may be designed to pivot away from the rear door, if the rack is supporting a substantial weight in equipment, the bikes or other cargo must be unloaded before the cargo rack is tilted to gain access to the rear of the vehicle. Several existing devices have employed springs or gas shock to balance the weight of equipment particularly bikes, to allow the loaded rack to be pivoted downwardly away from the rear door. However if the rack is unloaded it now becomes difficult to pivot because the force of the spring or gas shock must be overcome. In some circumstances considerable force must be exerted on the rack at the same time that a latch or release must be actuated. This results in needing a combination of strength and dexterity to move the rack towards or away from its carrying position behind the vehicle.
The usefulness of a cargo rack increases as the simplicity and ease of use increases. Potential purchasers of cargo racks for use with trailer hitch mounts behind vehicles are typically concerned not only with simplicity and ease of use but cost and durability.
What is needed is a mechanism for mounting an equipment rack to a trailer hitch which provides access to the rear of the vehicle and in which movement of the rack is not significantly affected by whether the rack is supporting equipment or is empty.
The equipment rack of this invention incorporates four linked members which mount an equipment rack support to a hitch insert. The linked members are formed by two pairs of pivotally linked arms which in turn are pivotally linked to the hitch insert and to an equipment rack mounting bracket. Each pair of linked arms provides three pivot bearings which have mutually parallel axes, the entire rack mechanism thus incorporates six pivot axes. The individual arms are constructed of torsionally stiff members. In the collapsed position the linked arms making up each pair are parallel and the equipment rack support and hitch insert are in juxtaposition. In the rearwardly extended position the arms making up each pair are substantially co-linear. As the equipment rack rotates to one side of the vehicle the arms assumed a bend but extended configuration. The equipment rack support and hitch insert are separated by a distance approximately equal to twice the length of an individual arm.
Each pivot bearing which attaches an arm to the rack support or the hitch insert is formed between structural extensions from the arms which overlie the arms and the rack support or hitch insert. These structural extensions prevent interference between the arms and the hitch insert and rack support when the arms pivot with respect to them. Similarly structural extensions extend from one of each pair of arms and overlie the connected arms to allow the arms to pivot without interference. For greater rigidity between the rack support and the hitch insert a mechanical link which locks the rack support to the hitch insert is provided when the linked members position the rack support and hitch insert in juxtaposition. Maximum rigidity is only required while the vehicle is in actual motion and the rack is retracted against the rear of the vehicle.
It is an object of the present invention to provide a mechanism for mounting an equipment rack to a vehicle trailer hitch which allows access to the rear door of the vehicle.
It is a further object of the present invention to provide a means for moving a loaded or empty rack away from the rear of a vehicle to gain access to the rear of the vehicle without the necessity of applying significant force.
Further objects, features and advantages of the invention will be apparent from the following detailed description when taken in conjunction with the accompanying drawings.